The researchers found that optimal use of these tools has been shown to reduce the risk of adverse effects by 3-7%, and to improve efficacy by 15–30%.

For the introduction of aldehyde oxidase into clinical practice, the association between aldehyde oxidase activity and AZA dose requirements should be positively confirmed.

The team reported that inosine triphosphatase assessment associated with adverse effects also shows promise.

Nucleoside diphosphate-linked moiety X-type motif 15 variants have been shown to predict myelotoxicity on thiopurines in East Asian patients.

However, the researchers noted that the impact of assessments of xanthine oxidase, glutathione S-transferase, hypoxanthine guanine phosphoribosyltransferase and inosine monophosphate dehydrogenase appears too low to favor incorporation into clinical practice.

Dr Moon and colleague concludes, "Measurement of thiopurine-related enzymes and metabolites reduces the risk of adverse effects and improves efficacy, and should be considered part of standard management."

"However, this approach will not predict or avoid all adverse effects, and careful clinical and laboratory monitoring of patients receiving thiopurines remains essential."